利用光学Thomson散射技术研究充气黑腔内的受激布里渊散射过程

Stimulated Brillouin Scattering (SBS) is one of the parametric instabilities that widely exist in the research filed of high energy density physics. However, in experiments with closed geometry, SBS is too complicated to be quantitatively predicted. This is one of the primary reasons for the failure of ignition in laser indirect-drive inertial confinement fusion (ICF).. This project will apply the optical Thomson scattering technique, which has been well developed in open-geometry experiments, to closed-geometry experiments with gas-filled hohlraums, so as to diagnose the temporal and spatial behavior of the ion acoustic wave (IAW) driven by SBS. By combining the IAW evolution information with the measured SBS scattered light, SBS process will be studied in details. The results will improve the physical understanding of SBS in gas-filled hohlraums, hence contributing to the quantitative prediction and effective mitigation of SBS in laser indirect-driven ICF.

以受激布里渊散射（SBS）为代表的参量不稳定性过程广泛地存在于高能量密度物理研究领域。然而，在封闭的实验位型下，SBS过程异常复杂，很难对其进行定量的预测。这也是激光间接驱动惯性约束聚变（ICF）至今仍未实现聚变“点火”的主要原因之一。. 本项目将把开放实验位型下发展成熟的光学Thomson散射技术应用到封闭的充气黑腔实验中，以实现对SBS驱动的离子声波（IAW）的全时空诊断。在此基础之上，结合IAW的时空演化信息与SBS散射光数据，研究SBS的细致演化过程。本项目的研究成果能够提升充气黑腔内SBS过程的物理理解，为激光间接驱动ICF中SBS过程的定量预测和有效抑制做出贡献。

受激布里渊散射（SBS）是间接驱动惯性约束聚变（ICF）研究中的一个关键过程。然而，传统的基于背向散射光诊断的研究方法，由于无法获得局域的SBS演化信息，极大地限制了对SBS的物理理解。本项目将光学Thomson散射诊断技术应用到充气黑腔这种封闭位型中，成功地实现了对SBS过程激发的离子声波（IAW）的局域诊断。实验获得的超热相干Thomson散射光谱与SBS散射光谱相结合，揭示了充气黑腔内SBS的时间演化行为。实验结果与模拟计算相结合，进一步揭示了SBS的激发区域，以及影响SBS的多种因素。本项目成功地建立了超热相干Thomson散射诊断技术，丰富了SBS的研究手段。另外，本项目也提升了对SBS的物理理解，为ICF研究中抑制SBS做出了重要贡献。